JP2001099309A - Shift controller for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift controller for a continuously variable transmission capable of surely corresponding to a demand of a driver such as down-shift expectation for acceleration and/or down-shift expectation for applying an engine brake, only by one mode switching operation, when a mode is changed from an automatic shift mode to a manual shift mode. SOLUTION: This controller is provided with a shift mode switching means for selectively switching an automatic shift mode and a manual shift mode, and an initial transmission gear ratio setting means for setting an initial transmission gear ratio just after switching the mode to a transmission gear ratio of an increasing side for increasing input rotating speed of a transmission in a transmission gear ratio in the automatic shift mode before switching the mode to prescribed rotating speed or more which is set beforehand, when the mode is switched from the automatic shift mode to the manual shift mode, by operation for the shift mode switching mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission having a manual shift mode function, and more particularly to a shift control technique in an initial stage of switching from an automatic shift mode to a manual shift mode.

[0002]

2. Description of the Related Art Conventionally, as a shift control device of a continuously variable transmission having a manual mode function, for example, Japanese Unexamined Patent Publication No.
The ones described in 196156 and JP-A-9-264416 are known.

The former publication aims to smoothly switch from the automatic shift mode to the manual shift mode without giving the driver a sense of incongruity, and the downshift side closest to the actual input rotation at the time of the switch is provided. A description is given of selecting a gear position that is a reaching input rotation and selecting a gear position that is the reaching input rotation on the upshift side closest to the actual input rotation at the time of switching.

[0004] The latter publication discloses that the driver can experience switching from the automatic transmission mode to the manual transmission mode and that the driver needs to apply the engine brake by switching the transmission mode. For the purpose of setting the gear stage initial value line in the shift diagram,
At the time of switching from the automatic shift mode to the manual shift mode, a shift speed initial value corresponding to the vehicle speed is calculated, and based on the shift speed initial value, when the current shift speed is larger than the shift speed initial value and is on the high speed side. Set the shifted gear position to the initial gear position value, and if the current gear position is smaller than the initial gear position value, set the shifted gear position to the lower gear position closest to the current gear position to the initial gear position value. Is set so that the shift in the downshift direction is achieved.

[0005]

However, in the former prior art, the purpose of the driver actually switching from the automatic shift mode to the manual shift mode is to downshift or prepare for the next acceleration. Since the downshift is expected to apply the engine brake, the downshift operation must be further performed after the mode switching operation, and there is a problem that the operation is troublesome.

In the latter prior art, for example, when the current gear is slightly higher than the initial gear and is on the high gear side, the gear after switching is set to the initial gear. Therefore, although the downshift is performed when the shift mode is switched, the expected engine braking force is not generated due to a small change in rotation, and the downshift is performed with the same gear ratio width when the accelerator is frequently turned off. However, there is a problem that an expected engine braking force is not generated due to a small change in rotation. In other words, simply setting the shift direction to the downshift direction at the time of shifting the shift mode cannot satisfy the driver's request to apply the acceleration and the engine brake by the mode switching.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. When switching from the automatic transmission mode to the manual transmission mode, only one mode switching operation is required to expect a downshift for acceleration or an engine. An object of the present invention is to provide a shift control device for a continuously variable transmission that can reliably meet a driver's request of expecting a downshift for applying a brake.

[0008]

According to the first aspect of the present invention, there is provided an automatic transmission control means for setting an automatic transmission mode in which a transmission ratio is automatically changed in accordance with an operation state; A continuously variable transmission including: manual shift control means for setting a manual shift mode in which a fixed gear ratio can be sequentially selected from among shift speeds; and shift mode switching means for selectively switching between the automatic shift mode and the manual shift mode. When the automatic transmission mode is switched from the automatic transmission mode to the manual transmission mode by operating the transmission mode switching means, the initial transmission ratio immediately after the switching is changed to the transmission ratio in the automatic transmission mode before the switching. Initial speed ratio setting means is provided for setting the speed ratio on the increasing side to increase by at least a preset predetermined speed with respect to the transmission input speed. Characterized in that was.

According to a second aspect of the present invention, in the shift control device for a continuously variable transmission according to the first aspect, the manual shift control means has a fixed speed ratio for each of a plurality of shift speeds. When the initial gear ratio setting means is switched from the automatic gearshift mode to the manual gearshift mode, the highest gear position among the gear stages that increases to an input rotation speed equal to or higher than a predetermined rotation speed with respect to the current transmission input rotation speed. It is characterized in that it is means for setting the gear position.

[0010]

According to the first aspect of the present invention, when the automatic shift mode is selected by the shift mode switching means, the automatic shift control means controls the vehicle speed, the throttle opening, and the like. The gear ratio automatically changes according to the operating state of the vehicle. On the other hand, when the manual shift mode is selected by the shift mode switching means, the manual shift control means can manually select a fixed gear ratio from among a plurality of shift speeds by manual operation.

When the automatic transmission mode is switched from the automatic transmission mode to the manual transmission mode by operating the transmission mode switching means, the initial transmission ratio setting means sets the initial transmission ratio immediately after the switching to the automatic transmission mode before the switching. Is set to an increasing gear ratio that increases at least by a predetermined rotational speed at least with respect to the transmission input rotational speed at the gear ratio at.

That is, at the time of switching from the automatic transmission mode to the manual transmission mode, a downshift in which the transmission input rotational speed is increased by a predetermined rotational speed or more is always performed.
For example, a change in the transmission input rotation speed at a predetermined rotation speed is ensured even when the accelerator is OFF with a large demand for engine braking,
The engine braking force expected by the driver is generated.

Therefore, when switching from the automatic transmission mode to the manual transmission mode, only one mode switching operation does not require a downshift operation, and a downshift for acceleration or a downshift for applying engine braking is performed. It is possible to reliably meet the driver's demand for shift expectation.

According to a second aspect of the present invention, when the automatic speed change mode is switched to the manual speed change mode, the initial speed ratio setting means sets a fixed speed ratio for each of a plurality of shift speeds. On the manual shift control means side,
The highest shift speed among the shift speeds that increase to an input speed equal to or higher than the predetermined speed with respect to the current transmission input speed is set.

That is, the shift line closest to the current transmission input rotation speed (actual input rotation speed or input rotation speed corresponding to the target gear ratio before switching) is equal to or more than the rotation speed obtained by adding a predetermined rotation speed. Is set.

Accordingly, if a shift map for the manual shift mode is provided which defines a steady target input speed with respect to the output speed of the transmission, the input speed can be converted into a speed ratio by a simple process. At the time of mode switching, it is possible to set a speed ratio that increases to an input speed equal to or higher than a predetermined speed with respect to the current transmission input speed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shift control device for a continuously variable transmission according to the present invention will be described in detail with reference to the drawings.

[Construction of Transmission Unit of Continuously Variable Transmission and Transmission Control Apparatus] FIGS. 1 and 2 show a toroidal type continuously variable transmission equipped with a continuously variable transmission transmission control apparatus according to the present invention. 2 is a longitudinal sectional side view showing a transmission unit of the toroidal type continuously variable transmission, and FIG. 2 is a diagram showing a shift control device of the toroidal type continuously variable transmission.

First, a transmission unit, which is a main part of a toroidal type continuously variable transmission, will be described with reference to FIG. This transmission unit includes an input shaft 20 to which rotation from an engine (not shown) is transmitted. As shown in FIG. 1, the input shaft 20 has an end remote from the engine via a bearing 22 in a transmission case 21. And a central portion is rotatably supported in a middle wall 23 of the transmission case 21 via a bearing 24 and a hollow output shaft 25.

The input shaft 20 has an input cone disk 1
And the output cone disk 2 is supported on the hollow output shaft 25, and the input and output cone disks 1 and 2 are coaxially arranged such that the toroidal curved surfaces 1a and 2a face each other.

A pair of power rollers 3, 3 disposed on both sides of the input shaft 20 with the input shaft 20 interposed therebetween are interposed between the opposed toroidal curved surfaces 1a, 2a of the input / output cone disks 1, 2. The following configuration is adopted in order to pinch 3, 3 between the input and output cone disks 1, 2.

That is, a loading nut 26 is screwed into an end of the input shaft 20 on the bearing 22 side, and a cam disk 27 which is prevented from coming off by the loading nut 26 and is rotationally engaged on the input shaft 20; Loading cam 2 between the toroidal surface 1a and the end surface far from the toroidal surface 1a
The rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 via the loading cam 28.

Here, the rotation of the input cone disk 1 is transmitted to the output cone disk 2 via the rotation of the two power rollers 3, 3, and during this transmission, the loading cam 28 generates a thrust proportional to the transmission torque. The power rollers 3 are narrowed between the input and output cone disks 1 and 2 to enable the power transmission.

The output cone disk 2 has an output shaft 25
The output gear 29 is fitted on the output shaft 25 so as to rotate integrally therewith.

The output shaft 25 is further rotatably supported in an end cover 31 of the transmission case 21 via a radial / thrust bearing 30, and the input shaft 25 is provided with a separate radial / thrust bearing 32 in the end cover 31. The shaft 20 is rotatably supported. Here, the radial and thrust bearings 30 and 32 are butted so as not to approach each other at the start of the spacer 33, and the axis of the corresponding output gear 29 and the input shaft 20 are set so as not to be displaceable relative to each other. Make contact in the direction.

With the above configuration, the thrust acting between the input and output cone disks 1 and 2 by the loading cam 28 becomes an internal force that sandwiches the spacer 33 and does not act on the transmission case 21.

As shown in FIG. 2, the power rollers 3, 3 are rotatably supported by trunnions 41, 41. Each of the trunnions 41, 41 has a spherical joint 42 at its upper end.
Thus, the lower end is rotatably and swingably connected to both ends of the lower link 45 by the spherical joint 44.

The upper link 43 and the lower link 45 are supported by the spherical joints 46 and 47 at the center of the transmission case 21 so as to be vertically swingable.
41 can be moved up and down in synchronization with each other in opposite directions.

Thus, both trunnions 41, 41 are
A shift control device that shifts by vertically moving in synchronization with each other will be described with reference to FIG.

Each of the trunnions 41, 41 is provided with a piston 6, 6 for individually moving the trunnions 41 in the vertical direction.
1, 52 and lower chambers 53, 54 are defined. To control the strokes of the pistons 6 and 6 in opposite directions, a speed change control valve 5 is provided.

Here, the speed change control valve 5 has a spool-type inner valve element 5a and a sleeve-type outer valve element 5b slidably fitted to each other, and slides the outer valve element 5b to a valve case 5c. It is configured to be movably fitted.

The transmission control valve 5 has an input port 5d connected to a pressure source 55, one communication port 5e connected to the piston chambers 51 and 54, and the other communication port 5f connected to pistons 52 and 53 which know the piston. I do.

Then, the inner valve body 5a cooperates with the cam surface of the precess cam 7 fixed to the lower end of the one trunnion 41 via a bell crank type shift lever 8, and the outer valve body 5a
b to the step motor 4 as a speed change actuator,
Drive and engage in a rack and pinion type.

The operation command of the shift control valve 5 is given by the step motor 4 responsive to the actuator drive position command Asstep (step position command) to the outer valve body 5b as a stroke via a rack and pinion.

With this operation command, the outer valve body 5 of the shift control valve 5
b is relative to the inner valve body 5a from a neutral position, for example,
When the shift control valve 5 is opened by being displaced to the position shown in FIG. 2, the fluid pressure (line pressure PL) from the pressure source 55 is supplied to the chambers 52 and 53, while the other chambers 51 and 54 are drained. When the outer valve 5b of the transmission control valve 5 is displaced in the opposite direction from the neutral position with respect to the inner valve 5a and the transmission control valve 5 is opened, the fluid pressure from the pressure source 55 flows into the chambers 51 and 54. While being supplied, the other chambers 52 and 53 are drained, and the two trunnions 41 and 41 are displaced in the corresponding vertical directions in the figure via the pistons 6 and 6 by fluid pressure in opposite directions.

[0036] Thus both the power rollers 3 and 3, the rotation axis _{O 2} of the rotary shaft axis _{O 1} is output cone discs 1 and 2
Offset from the illustrated position (offset amount y)
Is the result in, at swing component force from the power rollers 3,3 are output cone discs 1 and 2 by nuclear offset, tilt about the oscillation axis O ₃ orthogonal to the rotation axis O ₁ of the self ( With the tilt angle φ), continuously variable transmission can be performed.

During such a gear shift, one trunnion 41
The precess cam 7 coupled to the lower end of the transmission gear 8 mechanically transmits the above-described vertical movement (offset amount y) and tilt angle φ of the trunnion 41 and the power roller 3 to the inner valve body 5 a of the transmission control valve 5 via the transmission link 8. Is fed back as indicated by x.

When the speed ratio command value corresponding to the actuator drive position command Asstep to the step motor 4 is achieved by the stepless speed change, the mechanical feedback via the precess cam 7 causes the speed change control valve 5 to operate. and the inner valve body 5a of, is returned to a relatively initial neutral position with respect to the outer valve member 5b, at the same time, both the power rollers 3,3, rotates the rotation axis O ₁ of input and output cone discs 1 and 2 Axis 0 ₂
By returning to the illustrated position intersecting with the above, it is possible to maintain the state of attainment of the speed ratio command value.

Since the aim of the control is to make the power roller tilt angle φ a value corresponding to the gear ratio command value, the precess cam 7 basically has to feed back only the power roller tilt angle φ. However, the reason why the power roller offset amount y is also fed back here is to provide a damping effect for preventing the shift control from becoming oscillating, thereby avoiding the hunting phenomenon of the shift control.

The actuator drive position command Asstep to the step motor 4 is set by the controller 61.

For this purpose, as shown in FIG. 2, a signal from a throttle opening sensor 62 for detecting an engine throttle opening TVO, a signal from a vehicle speed sensor 63 for detecting a vehicle speed VSP, and an input cone disk 1 are provided to the controller 61.
From the input rotation sensor 64 for detecting the rotation speed Ni (or the engine rotation speed Ne), a signal from the output rotation sensor 65 for detecting the rotation speed No of the output cone disk 2, and the transmission operating oil temperature TMP. signal from sly oil temperature sensor 66, the detecting the line pressure P _L from the hydraulic source 55 (normally detects from the internal signal of the controller 61 from controlling the line pressure P _L by the controller 61) the line pressure sensor 67 , A signal from the engine rotation sensor 68 for detecting the engine rotation speed Ne, a signal about range information from the inhibitor switch 60, UP / D
A signal for UP / DOWN information from the OWN switch 69, a selection mode signal from the mode selection switch 70, a torque down permission signal from the engine control device 310, and an A from the anti-skid control device (ABS) 320.
BS control signal, traction control device (TC
S) TCS control signal from 330 and constant-speed traveling device 34
An ASCD cruise signal from 0 is input.

The controller 61 sets an actuator drive position command Astep (shift command value) to the step motor 4 by the following calculation based on the above various input information.

[Configuration of Controller] In the present embodiment, the controller 61 is configured as shown in FIG.

The shift map selector 71 is provided with the sensor 6 shown in FIG.
The shift map is selected in accordance with various conditions such as the oil temperature TMP detected in 6 and whether or not the exhaust gas purifying catalyst is being activated.

The arrival input rotational speed calculating section 72 will explain the case where the shift map selected in this way is, for example, as shown in FIG.
From the throttle opening TVO and the vehicle speed VSP detected at 63, respectively, based on the shift map corresponding to the shift diagram in the same figure, the reached input speed to be the steady target input speed in the current operating state Search for and find Ni ^* .

The attained gear ratio calculation unit 73, by dividing the arrival input rotation speed Ni ^* by the transmission output rotational speed No detected by the sensor 65 of FIG. 2, a constant corresponding to the arrival input rotation speed Ni ^* A target speed ratio i ^* , which is a target speed ratio, is determined.

The shift time constant calculation unit 74 calculates a selected range (forward normal travel range D, forward sports travel range Ds),
Vehicle speed VSP, throttle opening TVO, engine speed N
e, an accelerator pedal operation speed, a signal relating to the amount of torque reduction from a torque-down control device (not shown), a torque-down permission signal, an anti-skid control signal, a traction control signal, a constant speed traveling signal, and a target gear ratio Ratio0 described later. The first speed change time constant Tg1 and the second speed change time constant Tg2 of the speed change control are set in accordance with various conditions such as a speed ratio deviation RtoERR with respect to the target speed ratio i.
A deviation Eip between ^* and the target gear ratio Ratio0 is calculated.

Here, the first shift time constant Tg set to correspond to the secondary delay system of the toroidal type continuously variable transmission.
The first and second shift time constants Tg2 are used to determine the shift speed by setting the shift responsiveness to the attained speed ratio i ^* . The target speed ratio calculation unit 75 calculates the attained speed ratio i ^* by the first speed change. The target speed ratio Ratio0 and the intermediate speed ratio Ratio00 at each transitional time and time for realizing with the speed response determined by the time constant Tg1 and the second speed time constant Tg2 are calculated, and only the target speed ratio Ratio0 is output.

The input torque calculator 76 calculates the transmission input torque Ti by a known method. First, the engine output torque is calculated from the throttle opening TVO and the engine speed Ne, and then the input / output speed of the torque converter is calculated. The torque ratio t of the torque converter is determined from the speed ratio which is the (Ne, Ni) ratio, and finally, the transmission input torque Ti is calculated by multiplying the engine output torque by the torque ratio t.

The torque shift compensating speed ratio calculating unit 77 eliminates a torque shift (incorrect speed ratio) peculiar to a toroidal-type continuously variable transmission from the transient target speed ratio Ratio0 and the transmission input torque Ti. Is calculated.

Here, a supplementary explanation of the torque shift of the toroidal type continuously variable transmission is as follows. During transmission of the toroidal type continuously variable transmission, the power rollers 3, 3 are transmitted as described above.
Is compressed between the input and output cone disks 1 and 2, the trunnion 41 is deformed. As a result, the position of the precess cam 7 at the lower end of the trunnion changes, and the mechanical feedback system including the precess cam 7 and the speed change link 8 A change in the path length is caused, thereby causing the torque shift.

Therefore, the torque shift of the toroidal type continuously variable transmission depends on the target speed ratio Ratio0 and the transmission input torque Ti, and the torque shift compensation speed ratio calculation unit 77 calculates the torque shift compensation speed ratio from these two-dimensional maps. TSrto is obtained by search.

The actual speed ratio calculating section 78 calculates the transmission output speed N by detecting the transmission input speed Ni by the sensor 65 in FIG.
By dividing by o, the actual gear ratio Ratio is calculated. The gear ratio deviation calculator 79 calculates the target gear ratio Rat.
The actual gear ratio Ratio is subtracted from io0, and the gear ratio deviation RtoERR (= Ratio0-Ra) between the two.
tio).

The first feedback (FB) gain calculating section 80 is a well-known PID corresponding to the speed ratio deviation RtoERR.
It is used when calculating a gear ratio feedback correction amount by control (P is proportional control, I is integral control, and D is differential control).
First proportional control feedback gain fbpDAT to be set according to transmission input rotation speed Ni and vehicle speed VSP
A1, feedback gain fbiDATA for integral control
1, and feedback gain fbdDAT for differential control
A1 is obtained.

These first feedback gains fbp
DATA1, fbiDATA1, fbdDATA1 are
A two-dimensional map of the transmission input rotation speed Ni and the vehicle speed VSP is determined in advance, and the map is obtained from the transmission input rotation speed Ni and the vehicle speed VSP based on the map.

[0056] The second feedback (FB) gain calculation unit 81, among the feedback gain used when calculating the speed ratio feedback correction amount by the PID control, set in accordance with the transmission hydraulic oil temperature TMP and the line pressure P _L Feedback gain fbp for second proportional control to be performed
DATA2, feedback gain fbiD for integral control
ATA2 and differential control feedback gain fbd
DATA2 is obtained respectively.

These second feedback gains fbp
DATA2, fbiDATA2, fbdDATA2 are
A two-dimensional map of the hydraulic oil temperature TMP and the line pressure P _L is determined in advance, and the map is obtained from the hydraulic oil temperature TMP and the line pressure P _L based on this map.

The feedback gain calculating section 83 multiplies the first feedback gain and the second feedback gain by the corresponding ones, and obtains a feedback gain fbpDATA for proportional control (= fbpDATA).
1 × fbpDATA2), feedback gain fbiDATA for integration control (= fbiDATA1 × fbiDA)
TA2) and feedback gain fbd for differential control
DATA (= fbdDATA1 × fbdDATA2) is obtained.

The PID control unit 84 uses the feedback gain obtained as described above to determine the speed ratio deviation RtoE.
To calculate the gear ratio feedback correction amount FBrto by the PID control according to the RR, the gear ratio feedback correction amount by the proportional control is calculated as RtoERR × fbpD.
ATA, then the speed ratio feedback correction amount by integral control is obtained by ∫RtoERR × fbiDATA, the speed ratio feedback correction amount by differential control is obtained by (d / dt) RtoERR × fbdDATA, and finally the sum of these three values Is the gear ratio feedback correction amount FBrto (= RtoERR × f) by the PID control.
bpDATA + @ RtoERR × fbiDATA + (d /
dt) RtoERR × fbdDATA).

The target gear ratio corrector 85 calculates the target gear ratio Ra
tio0 is corrected by the torque shift compensation speed ratio TSrto and the speed ratio feedback correction amount FBrto, and the corrected target speed ratio DsrRTO (= Ratio0 + TSrt)
o + FBrto). The target step number (actuator target drive position) calculation unit 86 obtains a target step number (actuator target drive position) DsrSTP of the step motor (actuator) 4 for realizing the corrected target gear ratio DsrRTO by searching a map.

Step motor drive position command calculator 87
If the step motor 4 cannot be displaced to the target step number DsrSTP during one control cycle even at the limit drive speed of the step motor 4 set by the step motor drive speed setting unit 88 based on the transmission working oil temperature TMP or the like, If the achievable limit position achievable at the limit drive speed of the motor 4 is set as a drive position command Astep to the step motor 4, and the step motor 4 can be displaced to the target step number DsrSTP in one control cycle, It is assumed that the target step number DsrSTP is directly used as the drive position command Asstep for the step motor 4.

Accordingly, the drive position command Asstep can always be regarded as the actual drive position of the step motor 4.

The step motor 4 is driven by a drive position command Ast.
The outer valve body 5b of the transmission control valve 5 is displaced in the direction and position corresponding to ep through the rack and pinion, and the toroidal-type continuously variable transmission can be shifted in a predetermined manner as described above. it can.

By this speed change, the drive position command Astep
When the gear ratio command value corresponding to
The mechanical feedback via 7 is the internal valve of the shift control valve 5
Do the body 5a, the initial neutral position relatively to the outer segment 5b
And at the same time, both power rollers 3, 3 rotate
Axis 0₁Is the rotation axis 0 of the input and output cone disks 1 and 2. ₂
By returning to the illustrated position intersecting with
The achievement state can be maintained.

In the present embodiment, a step motor follow-up determination section 89 is additionally provided.

This step motor follow-up determination section 89
Means that the stepper motor 4 has the corrected target gear ratio DsrRTO
It is determined below whether or not it is possible to follow the target step number (actuator target drive position) DsrSTP corresponding to.

That is, the judging section 89 first determines the step number deviation (actuator driving position deviation) △ STP between the target step number (actuator target driving position) DsrSTP and the driving position command Astep which can be regarded as the actual driving position. Ask.

Then, the judgment unit 89 determines whether or not the stepping motor drive speed has been set by the stepping motor driving speed setting unit 88 as described above.
Is the lower limit of the step number deviation (actuator drive position deviation) that cannot be eliminated in one control cycle _{ step number deviation from STP _LIM (actuator drive position deviation)} ST
When P is small (△ STP <△ STP _LIM ), the step motor 4 sets the target number of steps (actuator target drive position) DsrS corresponding to the corrected target speed ratio DsrRTO.
It is determined that the TP can be followed, and conversely, △ STP ≧ △ ST
When P _LIM, it is determined that the step motor 4 cannot follow the target step number (actuator target drive position) DsrSTP.

If the determination unit 89 determines that the step motor 4 can follow the target step number (actuator target drive position) DsrSTP corresponding to the corrected target gear ratio DsrRTO, the PID control unit 84 has already explained. The calculation of the gear ratio feedback correction amount FBrto by the same PID control is continued.

In this manner, the step motor 4 is driven to the target step number (actuator target drive position) DsrST
If it is determined that P cannot be followed, the gear ratio feedback correction amount by the integral control ∫RtoERR × fbiD
The PID control unit 84 is instructed to hold ATA at the value at the time of the determination.

Further, in the present embodiment, when the step motor driving position command calculating section 87 cannot displace the step motor 4 to the target step number DsrSTP in one control cycle even at the limit driving speed of the step motor 4, the step motor 4 is set as a drive position command Astep to the step motor 4, and the drive position command Astep is set as an actual drive position of the step motor 4 by the determination unit 89 to follow the step motor. The actual drive position of the step motor 4 required for performing such a follow-up determination is detected by the drive position command Astep from the speed change control device to the step motor 4, as described above. Inexpensive for the following determination without depending on the actual measurement of the actual driving position of the step motor 4 It can be carried out.

In the present embodiment, the step motor follow-up determination section 89 determines a step number deviation (actuator drive) between the target step number (actuator target drive position) DsrSTP and the actual drive position (drive position command) Asstep. When the position deviation △ STF is smaller than the reference deviation 判定 STP _LIM determined according to the limit driving speed of the step motor 4 (△ STP <△ STP
_LIM ), and the stepper motor 4 outputs the corrected target gear ratio Dsr.
It is determined that the target step number (actuator target drive position) DsrSTP corresponding to the RTO can be followed, and when △ STP ≧ △ STP _LIM , the step motor 4 sets the target step number (actuator target drive position) D
The oil temperature TM is determined to be incapable of following srSTP.
The determination that the stepping motor 4 can follow can be reliably performed regardless of the limit driving speed of the stepping motor 4 that varies in various ways such as P.

[Overall Shift Control] When the controller 61 shown in FIG. 2 is constituted by a microcomputer, the shift control described with reference to FIG. 3 is executed by the programs shown in FIGS.

FIG. 5 shows the entire shift control, and this routine is executed, for example, every 10 ms. First, in step 91, the shift time constant calculation unit 74 (FIG. 3)
Vehicle speed VS detected by vehicle speed sensor 63 (FIG. 2)
P, the engine speed Ne detected by the engine speed sensor 68 (FIG. 2), the transmission input speed Ni detected by the input speed sensor 64 (FIG. 2), and the throttle opening sensor 62 (FIG. 2) It reads the throttle opening TVO, range information (automatic shift (D) range, sports running (S) range, etc.) from the inhibitor switch 60 (FIG. 2).

Next, at step 92, the reached input speed calculating section 72 (FIG. 3) calculates the actual speed ratio Ratio by dividing the input speed Ni by the transmission output speed No. Next, at step 93, the reached input rotational speed Ni is calculated from the throttle opening TVO and the vehicle speed VSP based on the shift map as shown in FIG.
Search for ^* and ask.

Next, at step 94 as the reaching speed ratio setting means, the reaching speed ratio calculating section 73 (FIG. 3)
The attained speed ratio i ^* is calculated by dividing the attained input speed Ni ^* by the transmission output speed No. Next, in step 95 as the deviation calculating means, the shift time constant calculating unit 74 (FIG. 3) uses the target speed ratio Ratio0 calculated in the previous routine from the attained speed ratio i ^* (this is calculated in a later step 99). ) Is subtracted to obtain the deviation E
Calculate ip.

Next, at step 96, it is determined whether or not there is a stepped shift by mode switching and manual shift (hereinafter referred to as "switch shift"). Specifically, in response to a selection mode signal from the mode selection switch 70 (FIG. 2), the presence or absence of switching between the power mode and the snow mode is detected, and a manual range signal is output from the inhibitor switch 60 (FIG. 2). UP / DO while detecting
It is determined whether a signal for UP / DOWN information has been detected from the WN switch 69 (FIG. 2). Next, in step 97 and step 98 as mode setting means and step 99 as target gear ratio setting means, the shift time constant calculation unit 74 (FIG. 3) sets the time constant calculation mode to the first
And the second speed change time constants Tg1 and Tg2 and the target speed ratio R
ratio0 and the intermediate speed ratio Ratio00 are calculated.

Thereafter, in step 100, the torque shift compensation speed ratio calculating section 77 (FIG. 3) outputs the target speed ratio R
A torque shift compensation speed ratio TSrto is calculated from a map relating to atio0 and the transmission input torque Ti. Next, in step 101, the PID control unit 84 (FIG. 3) calculates the gear ratio feedback correction amount FBrto by PID control. Next, in step 102, the target gear ratio correction unit 85 (FIG. 3) outputs the target gear ratio R
The corrected target speed ratio DsrRTO is calculated by adding the torque shift compensation speed ratio TSrto and the speed ratio feedback correction amount FBrto to atio0. Next, at step 103, a drive position command Asstep to the step motor 4 (FIG. 2) is calculated, and this routine ends.

[Shift Control in Manual Shift Mode] FIG. 6 is an overall flowchart showing shift control processing in the manual shift mode in the shift control program.

First, at step 104, a manual mode system switch (inhibitor switch 60 and UP / D
OWN switch 69) switch status (ON, OFF)
Is input, and the process proceeds to step 105 (Japanese Unexamined Patent Application Publication No. 9-196).
No. 156, see FIG. 8).

At step 105, the input state of the control switch signal (M range signal, up signal, down signal, gate signal) is determined, and the routine proceeds to step 106. If the abnormal state continues for a set time or more based on the input state determination of the control switch signal, it is determined that the manual mode switch is abnormal.

In step 106, the shift state (initial state, downshift state,
(Upshift state, steady state) is determined and step 1
Go to 07 or later.

In step 107, when the previous traveling mode is other than the manual transmission mode (automatic transmission mode) and the current traveling mode is the manual transmission mode, the initial state immediately after the transmission mode is switched to the manual transmission mode. It proceeds to step 108,
Initial processing (FIG. 7) is executed.

In step 109, the shift state (downshift state, upshift state, steady state) in the manual shift mode is determined based on the combination of the M range signal and the previous and current up signal, down signal, and gate signal. You.

If it is determined in step 109 that the downshift is in the down signal ON state, step 11 is executed.
The process proceeds to 0, and the downshift state process (FIG. 8) is executed.

If it is determined in step 109 that the up signal is in the upshift state in which the up signal is turned on, step 11 is executed.
Then, the process proceeds to 1 to execute an upshift state process (FIG. 9).

If it is determined in step 109 that the vehicle is in a steady state that is neither a downshift state nor an upshift state, the flow advances to step 112 to perform processing in a steady state (FIG. 10).
Is executed.

[Initial Processing in Manual Transmission Mode] FIG. 7 is a flowchart showing the initial processing in the manual transmission mode in the transmission control program (corresponding to the initial transmission ratio setting means).

In step 113, the input rotation sensor 64
Thus, the input rotation InpREV (= Ni) of the transmission is read.

In step 114, after switching from the automatic transmission mode to the manual transmission mode, the minimum input rotation to be achieved is set to the input rotation InpREV by the set rotation DMOF.
Calculated by adding ST (InpREV + DMOFS
T).

At step 115, the vehicle speed VspSEN (= VSP) is read by the vehicle speed sensor 63.

In step 116, the arrival input rotation DsrREV corresponding to the vehicle speed VspSEN at each gear position (n)
n (= Ni ^* ) is calculated.

In step 117, DsrREVn ≧
The gear position of the highest gear among the gear positions satisfying (InpREV + DMOFST) is selected.

When the automatic shift mode is switched to the manual shift mode by operating the select & shift lever (shift mode switching means) (not shown), the initial processing shown in FIG. 7 is executed. The initial speed ratio immediately after the switching is set to an increasing speed ratio that increases by at least the set rotation DMOFST with respect to the input rotation speed InpREV of the transmission at the speed ratio in the automatic transmission mode before the switching.

That is, at the time of switching from the automatic transmission mode to the manual transmission mode, the transmission input speed Inp
A downshift in which the REV rises by more than the set rotation DMOFST is performed. For example, even when the accelerator is OFF with a large demand for engine braking, a change in the input rotation speed InpREV that is higher than the set rotation DMOFST is secured, and the engine brake expected by the driver is obtained. Force is generated.

Incidentally, in the case of selecting a gear position that is the down-shift-side reaching input rotation closest to the actual input rotation at the time of the conventional mode switching, as shown in FIG. When the actual input rotation is performed, the downshift is performed to the manual fourth speed. On the other hand, in the present invention, as shown in FIG. 11, for example, the set rotation DMOFST is changed to DMOFST = 500
In the case of rpm, if there is an actual input rotation in the area indicated by hatching at the time of mode switching, the downshift is performed to the manual fourth speed. In other words, manual 4th gear is 50
Even if there is an actual input rotation in the rotation speed region of 0 rpm or less, the downshift to the third speed is performed instead of the downshift to the fourth speed. In particular, while the change in the gear ratio becomes large in the coast region, the change in the high rotation region is small,
This shows that the engine brake request at the time of accelerator OFF can be met.

Therefore, at the time of switching from the automatic transmission mode to the manual transmission mode, only one mode switching operation to the select & shift lever does not require a downshift operation, and a downshift for acceleration or an engine is expected. It is possible to reliably meet the driver's request of expecting a downshift for applying a brake.

In the initial processing shown in FIG. 7, when the mode is switched from the automatic speed change mode to the manual speed change mode, the input of the current transmission is changed on the manual speed change control side having a fixed speed ratio for each of a plurality of speeds. Rotational speed InpR
As compared with EV, the gear position is set to the high gear position among the gear positions rising to the input rotation speed equal to or higher than the set rotation DMOFST, so that the vehicle speed VSP (= the output rotation speed of the transmission) is reached as shown in FIG. If a shift map for a manual shift mode that defines the input rotation Ni ^* (= steady target input rotation) is prepared, the current speed can be changed at the time of mode switching by a simple process that does not convert the input rotation speed into a gear ratio. It is possible to set a transmission ratio that increases to an input rotation speed equal to or higher than the set rotation DMOFST with respect to the transmission input rotation InpREV.

[Processing in Downshift State in Manual Shift Mode] FIG. 8 is a flowchart showing processing in a downshift state in manual shift mode in a shift control program.

In step 118, it is determined whether or not the vehicle speed VSP is equal to or higher than a predetermined value.
9 and in the case of NO, proceed to step 120.

In step 119, when the vehicle speed VSP is equal to or higher than a predetermined value, VDC (Vehicle Dynamics.
Control) operation is determined, and if the operation is performed, the process proceeds to step 122, and the downshift is prohibited. If the operation is not performed, the process proceeds to step 120. Here, VDC is
This system automatically adjusts the brake control force in accordance with the difference between the target slip amount and the actual slip amount of the vehicle and controls the engine output, thereby automatically improving running stability.

In step 120, N
If it is determined to be O, or if it is determined to be inactive in step 119, it is determined whether or not the gear position SftPOS is the first speed (minimum speed), and if YES, proceed to step 122; Proceed to step 121.

In step 121, N
If it is determined to be O, it is determined whether or not the target input rotation after the downshift is equal to or greater than a predetermined value in the maximum rotation range, and if YES, the process proceeds to step 122 to prohibit the downshift, thereby causing the engine to overrev (overspeed). Is prevented and N
In the case of O, proceed to step 123.

In step 122, V in step 119
When it is determined that the DC operation is performed, when it is determined that the gear position is the first speed in step 120, and when it is determined that the target input rotation after the downshift is equal to or more than a predetermined value in the maximum rotation range. , Downshifting is prohibited (the current gear position is maintained).

In step 123, if the vehicle speed VSP is less than the predetermined value in step 118, the gear position is other than the first speed in step 120, and the target input rotation after the downshift is less than the predetermined value in the maximum rotation range in step 121. When it is determined, a downshift is performed in which the gear is shifted to the lower gear by one speed.

[Process in Upshift State in Manual Shift Mode] FIG. 9 is a flowchart showing the process in the upshift state in the manual shift mode in the shift control program.

In step 124, it is determined whether or not the vehicle speed VSP is equal to or higher than a predetermined value.
The process proceeds to step 5, and if NO, the process proceeds to step 126.

In step 125, when the vehicle speed VSP is equal to or higher than the predetermined value, it is determined whether or not the vehicle is in VDC operation. If the vehicle is operating, the process proceeds to step 128, and upshift is prohibited.

At step 126, N
If it is determined to be O, or if it is determined to be inactive in step 125, it is determined whether the gear position SftPOS is the sixth speed (highest gear), and if YES, the process proceeds to step 128; Proceed to step 127.

In step 127, N
When it is determined to be O, the vehicle speed VSP is changed to the target gear SftP.
It is determined whether the vehicle speed is equal to or higher than the auto-down vehicle speed calculated based on the OS, and if YES, the process proceeds to step 129, and NO
In the case of (1), the process proceeds to step 128, in which upshift is inhibited to prevent up / down shift interference.

At step 128, V
When it is determined that the DC operation is performed, when it is determined in step 126 that the gear position is the sixth speed, or when it is determined that the vehicle speed is less than the auto down vehicle speed, the upshift is prohibited (the current gear Position is maintained).

In step 129, when it is determined in step 124 that the vehicle speed VSP is less than the predetermined value, in step 126 that the gear position is other than the sixth speed, and in step 127 that the vehicle speed is equal to or higher than the auto down vehicle speed, the speed is increased by one speed. An upshift for shifting to the gear side is executed.

[Process in Steady State in Manual Shift Mode] FIG. 10 is a flowchart showing a process in a steady state in the manual shift mode in the shift control program.

In step 130, it is determined whether or not the target input rotation is equal to or greater than the auto-up rotation AUPREV.
In the case of ES, the process proceeds to step 134, in which the engine is automatically upshifted, thereby preventing overrev (overspeed) of the engine.

In step 131, when the target input rotation is less than the auto-up rotation AUPREV, it is determined whether or not the vehicle speed VSP is equal to or higher than the auto-down vehicle speed calculated based on the target shift speed SftPOS.
32, the current gear position is maintained, and in the case of NO, the process proceeds to step 133, and the downshift is performed automatically. This automatic down control is performed basically for the purpose of returning to the lowest gear before the stop because the continuously variable transmission cannot change the gear during stop.

[0116] The present invention is not limited to the above embodiment, and many modifications and variations are possible.

For example, in the above-described embodiment, a case has been described in which the transmission control device for a continuously variable transmission according to the present invention is applied to a toroidal type continuously variable transmission. It can also be applied to transmissions.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a toroidal type continuously variable transmission including a shift control device for a continuously variable transmission according to the present invention.

FIG. 2 is a vertical sectional front view showing the toroidal-type continuously variable transmission shown in FIG. 1 together with a shift control system thereof.

FIG. 3 is a functional block diagram of a shift control executed by a controller of FIG. 2;

FIG. 4 is a shift diagram illustrating a shift pattern of the continuously variable transmission.

FIG. 5 is a flowchart showing the entire shift control program of the shift control device for the continuously variable transmission according to the present invention.

FIG. 6 is an overall flowchart showing a shift control process in a manual shift mode in a shift control program.

FIG. 7 is a flowchart showing an initial process in a manual shift mode in a shift control program.

FIG. 8 is a flowchart showing a downshift state process in a manual shift mode in a shift control program.

FIG. 9 is a flowchart showing processing in an upshift state in a manual shift mode in a shift control program.

FIG. 10 is a flowchart showing a steady state process in a manual shift mode in a shift control program.

FIG. 11 is a diagram showing a manual shift map showing an area downshifted to a manual shift fourth speed when switching from the automatic shift mode to the manual shift mode in the present invention.

FIG. 12 is a diagram showing a manual shift map showing an area where downshifting to a manual shift fourth speed is performed when switching from the automatic shift mode to the manual shift mode in the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input cone disc 2 Output cone disc 3 Power roller 4 Step motor 5 Shift control valve 6 Piston 7 Precess cam 8 Shift link 20 Input shaft 28 Loading cam 41 Trunnion 43 Upper link 45 Lower link 60 Inhibitor switch 61 Controller 62 Throttle opening sensor 63 Vehicle speed sensor 64 input rotation sensor 65 output rotation sensor 66 oil temperature sensor 67 line pressure sensor 68 engine rotation sensor 69 UP / DOWN switch 70 mode selection switch 71 shift map selection unit 72 reaching input rotation speed calculation unit 73 reaching gear ratio calculation unit 74 Shift time constant calculation unit 75 Target gear ratio calculation unit 310 Engine control switch 320 Anti-skid control device 330 Traction control device 340 Constant-speed traveling device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masatoshi Akanuma Nissan Motor Co., Ltd., 2nd Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Mitsuru Watanabe 2nd Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. 72) Inventor Shigeki Shimanaka 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Hiroyasu Tanaka 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Junya Takayama F-term (reference) in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa 3J052 AA12 BA13 CA21 DB01 GC42 GC44 GC46 HA13

Claims (2)

[Claims] An automatic transmission control means for automatically changing a transmission gear ratio in accordance with an operation state; and a manual transmission mode in which a fixed transmission gear ratio can be sequentially selected from a plurality of gear positions by manual operation. And a shift mode switching means for selectively switching between the automatic shift mode and the manual shift mode. When the mode is switched from the automatic transmission mode to the manual transmission mode, the initial transmission ratio immediately after the switching is set to at least a predetermined predetermined rotation speed with respect to the transmission input rotation speed at the transmission ratio in the automatic transmission mode before the switching. A shift control device for a continuously variable transmission, comprising an initial speed ratio setting means for setting the speed ratio on the increasing side to increase. 2. The speed change control device for a continuously variable transmission according to claim 1, wherein the manual speed change control means has a fixed speed ratio for each of a plurality of shift speeds, and When switching from the shift mode to the manual shift mode, the means for setting the highest shift speed among the shift speeds that increase to an input speed equal to or higher than a predetermined speed with respect to the current transmission input speed. A shift control device for a continuously variable transmission.